Road, although not smooth, decidedly driveable in the end (12)
I believe the answer is:
thoroughfare
'road' is the definition.
(I know that thoroughfare is a type of road)
'although not smooth decidedly driveable in the end' is the wordplay.
'although' becomes 'tho'' (synonyms).
'not smooth' becomes 'rough' ('rough' is the opposite to 'smooth').
'decidedly' becomes 'far' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in the end' says to take the final letters.
The last letter of 'driveable' is 'e'.
'tho'+'rough'+'far'+'e'='THOROUGHFARE'
Can you help me to learn more?
(Other definitions for thoroughfare that I've seen before include "highway" , "Public way or street" , "Public road" , "Access - road" , "Road or path" .)